The Histopathology Core is an ongoing established Core facility that was first set up at the time of the last competitive renewal. The ll goal of the Histopathology Core is to enhance and facilitate the conduct of research by individual Research Units that require support for histology, immunostaining, and imaging studies. The Core offers the following services to Program Project members: 1. Fixation, processing, embedding, cataloging, and storage of tissues and cultured ceils: a. Collection and fixation of tissues and cultured cells; b. Freezing of tissues, processing and embedding in paraffin, preparation of cytocentrifuged specimens; c. Cataloging and storage of tissues. 2. Sectioning of frozen and paraffin-embedded tissues: a. Preparation of frozen sections; b. Preparation of paraffin sections. 3. Histochemical and immunohistological staining procedures, in situ hybridizations: a. Routine and specialized histochemical staining, e.g., hematoxylin/eosin, PAS, or detection of 13- galactosidase; b. Imrnunohistological stains using monoclonal or polyclonal antibodies, and enzyme- or fluorochromebased detection, and, if necessary, antigen retrieval or signal amplification; c. In situ hybridizations, BrdU staining for detection of proliferating cells, TUNEL assays for detection of apoptotic cells. 4. Microscopic analysis and photodoeumentation: a. Bright-field, fluorescence, and confocal microscopy; b. Liaison for deconvolution microscopy in dedicated UCSD campus facility; c. Film-based and digital photodocumentation and archiving. 5. Facilitation of histological specialty services (electron microscopy, laser capture microdissection): a. Preparation of tissue and cell samples for electron microscopy and laser capture microdissection; b. Liaison for facilitation of these services by dedicated UCSD campus facilities for electron microscopy and laser capture microdissection. 6. Assistance with experimental design and data analysis of studies involving histological analysis: a. Advice on best experimental design in using histological methods for achieving specific scientific objectives; b. Assistance with histological evaluation and analysis. The Histopathology Core is fully equipped and has highly experienced personnel to provide these services at the highest technical quality in a cost-effective manner. Through flexible and close interactions with individual investigators of the Research Units, the Core meets the specific histopathologic needs of Program members in achieving their scientific objectives.